Piston type fluid meter



Feb. 3, 1953 w. H. MARSH 2,627,250

PISTON TYPE FLUID METER Filed March 6, 1947 INVENTOR. Walter H. Marsh attorneys Patented Feb. 3, 1953 PIS'I'QN TYPE FLUID METER Walter H. Marsh, Grafton, Pa, assignor to Rockwell Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application March 6, 1947, Serial No. 732,763

1 Claim.

This invention relates to fluid meters of the positive displacement type, and in particular to that type of displacement meters known as piston meters.

In meters of this type, a series of reciprocating pistons are actuated by the pressure of the fluid flowing through the system in which the meter is installed, to rotate a crankshaft connected to a register for indicating the total volume of fluid which has passed through the meter. The pistons, in their movement, actuate a suitable valve member to control the entrance of the fluid to the working side of the pistons during their working stroke and the exhaust of the fluid from the same side of the pistons and its discharge through a suitable outlet back into the line through which the fluid is flowing.

The illustrated embodiment is of the same general type as those illustrated in the Patent No. 2,106,651, issued January 25, 1938, to Walter H. Parker et a1., and the general theory of operation and some of the details of construction are the same as the meter shown in that patent.

I have, however, provided several improvements which, among other things, have the effect of reducing corrosion and wear in the meter parts, whereby the life of the meter is substantially extended and the cost of repair and replacement of worn or corroded parts is reduced. One of these improvements consists in the reconstruction of the meter so that it may be arranged in the piping system with which it is used in such manner that the fluid flows through the meter without being trapped in any pockets or the like wherein impurities such asdirt or sludge, etc., will settle out and remain in the meter so that they get into the working parts thereof to cause their rapid wear or deterioration. When meters of this type are used to measure the rate of substances such as crude oil, the fact that no pockets are provided to allow the impurities in the oil to settle out and impair the operation of the meter is an important factor in extending the life and reducing the Wear' of the moving parts of the meter. life of the meter by using materials in the construction thereof that have improved characteristics of corrosion resistance and Wear resistance.

Accordingly, it is the primary object of my invention to provide an improved fluid meter of such construction that it will be subject to comparatively little wear andwill accordingly require :a minimum of parts replacement and will have an extended life.

It is another important object of my invention I have also increased the L to provide a novel fluid meter having no pockets to collect dirt or sludge or other impurities and which allows these impurities to pass out of the meter with the fluid being measured so that they are not entrapped within the meter to cause wear or corrosion of the parts.

It is another object of my invention to provide a fluid meter having its working elements composed of materials of high corrosion resistance and with a relatively low coefiicient of friction with respect to the parts with which they 00-- operate.

Other objects will become apparent as the description proceeds in connection with the accompanying drawings, wherein:

Figure 1 is a vertical sectional view substantially through the center of a meter;

Figure 2 is a vertical sectional View of the valve shown in Figure 1 and its cooperating seat and passageways, but with the valve rotated through an angle ofdegrees from the position shown in Figure 1; and

Figure 3 is a partial sectional view, substantially along the line 33 of Figure 1.

Referring to the drawings, the meter comprises a casing Ill having four integral cylinders arranged in the same horizontal plane and at angles of 90 degrees to each other. Shown in Figure 1 are two coaxial cylinders 12 and I4, and a third cylinder It at right angles to the cylinders l2 and M. The fourth cylinder, which does not appear in the figure, is coaxial with the cylinder 86, as will be understood. At their inner ends the upper portions of the cylinders terminate in a tubular wall I! forming a central passageway I8 in the upper part of the casing. The wall I! forming the passageway l8 terminates at its upper end-in a horizontal annular surface 20.

Centrally disposed within the passageway I8 is a spider having an annular ring 22 and a coaxial hollow cylindrical hub 24, which is connected to and integral with the ring 22 by means of three equally spaced webs or spokes 26. The ring 22 is seated within an annular seat 28 adjacent thebottom of the passageway l8, and is securely affixed thereto as by means of cap screws 35). Fixedly secured within the central bore of the hub 24, at the top and the bottom thereof respectively, are bearing bushings 32 and 34 respectively, which provide bearings for a vertical crank shaft 36. In order to provide a minimum of friction between the bearings and the crank shaft, I form the bearings of a laminated. thermosetting plastic, such as Micarta. This materlal is very resistant to corrosion, has good compressive strength, good dimensional stability, low moisture absorption, and a low coefficient of fric tion with respect to metals such as the steel of the crank shaft 36. While Micarta is given as an example of the material used for these bushings and in other parts of the meter structure, as will be apparent as the description proceeds, it is to be understood that any suitable plastic having the characteristics described above can be used.

The inner walls of the cylinders I2, M, etc., are provided with liners 38 of brass, the liners being tightly fitted within the cylinders but in such manner that they may be removed for replacement. In order to decrease the corrosion of the liners 38 by the fluid which is being metered, and also to decrease the wear resulting from the action or the pistons within the cylinders, the inner surfaces of the liners 38 are chromium-plated and polished.

Each cylinder has mounted for reciprocating motion therein a piston which, among other elements, comprises a head it. The pistons in the coaxial cylinders l2 and M are connected by a rigid Scotch yoke 42 having enlarged lugs 34 at its ends, the lugs being secured to the piston heads it! by machine screws '35. The outer faces of each piston head All is provided with a peripheral recess which receives a flexible washer d8 of rubber, leather or the like. Each recess is curved so that the washer i substantially cupshaped as shown, with its outer end portion lying against the chromium-plated inner surface of the liner 38. Each washer id is clamped within its recess 52 by an annular retainer 50, which is secured to the head 45! by machine screws 56.

An endless spring 56 is partially seated within a peripheral groove in the outer edge of the retainer and is of such diameter that it exerts an outward force around the entire periphery of the retainer 59 and pushes the flexible washer d3 into engagement with the chromium-plated surface of the liner 38.

The Scotch yoke 42 which connects the pistons in the cylinders l2 and M has a vertical slot therethrough extending transversely of the yoke, there being a roller 58 disposed between the vertical side walls of the slot and operable to have rolling engagement with the said side walls. A second Scotch yoke Eli joins the two coaxial pistons disposed in the cylinders at right angles to the cylinders 12 and I l, and this Scotch yoke Bil also has a vertical elongated transverse slot 62 shown in Figure l. A roller 64 is disposed within the slot 62 and the rollers 58 and 64 are rotatably mounted upon acrank pin 66 fixedly attached in vertical po ition to a crank arm 63 on the bottom end of the crank shaft 36. A valve, which will be described subsequently, controls the aplication of fluid pressure to the uter nds of the pistons disposed in the cylinders in such sequence that the pistons, through the Scotch yokes t2 and 60, will rotate the crank arm 68 in a horizcntal plane to turn the vertical crankshaft 3 in he manner understood by those skilled in th art and as is more fully shown and explained in the aforesaid patent to Parker et 2.1,, 2,106,651.

In order to reduce the wear of the rollers 58 and 64 upon the walls of the transverse slots in the yokes 42 and lit, the rectilinear side walls of the slots are provided with hardened stainless steel inserts as shown at it and 12 on the yoke 52. The crank arm 68 is provided with a slot to split it vertically and to the left of the crankshaft as shown in Figure 1, whereby it may be clamped securely to the crankshaft by a screw i l. The assembled shaft and arm are then drilled and a pin 16 inserted through the hole to lock the crank arm and crankshaft against relative movement. The crank pin 65 passes through a vertical bore in the crank arm 68 adjacent its outer end, and is fixed thereto in any suitable manner as by a tapered pin 78. The rollers 58 and 86 are journalled for rotation upon the crank pin 66, and are retained thereon by a washer til, a nut and a cotter pin 88 on its lower threaded end.

As mentioned before, one of the important provisions of my improved meter is a discharge outlet at the bottom thereof rather than near the top, so as to eliminate any pocket into which impurities may settle. As shown in Figure l, the bottom of the casing ill has a vertical bore 9%! which terminates in an annular planar surface 92. An outlet fitting E4 is seated within the bore cc and against the surface 92, there being a gasket as between the shoulder 92 and the fitting 94. The casing i9 and the fitting 94 are held in assembled relationship by means of cap screws 98 and cooperating lugs its and I02 on the casing it and the fitting 9-! respectively. The fitting 94 has an axial bore provided with standard pipe threads GM to receive the threaded end of an outlet pipe. The lower end of the fitting a l also provides a planar annular surface I95 to provide a seat for a cooperating flange which may be attached to the fitting 56 by cap screws engaged in the cap holes 5538. Thus the outlet pipe may be directly threaded into the fitting 94 or may be attached thereto by a suitable flange as will be understood.

The fitting Si l includes an integral structure comprising legs H0 extending upwardly into the body of the meter and terminating in a horizontal annular stop member H2 which provides a stationary abutment to engage the lugs on the ends of the Scotch yokes 152 and (ill, to thus limit the inward movement of the pistons. In the illuslirated embodiment therefore, no means is shown for calibrating the meter by adjusting the stroke of the pistons as disclosed in the previously mentioned Patent 2,106,651. The member H2, however, serves to absorb the shock of stopping the inward movement of the pistons instead of having it absorbed by the walls of the slots the Scotch yokes 52 and E0.

The casting which provides the casing iii of the meter is so cored as to provide a passageway Ht along the top of each cylinder i2, It, etc. Each passageway H4 terminates at its outerend at the outer end of its respective cylinder, and at its inner end in an upwardly directed section ending in a horizontal planar surface which includes the previously mentioned horizontal surface 2d at the upper end of the central passageway it. Thus the central passageway is is surrounded by four independent passageways H4 arranged at equal angles of degrees around the central passageway. A chamber H5 is formed above the casing It by a cover member i 3 which is secured to the top of the casing it by means of cap screws E28, and sealed to the top or the casing by a gasket 22. The chamber iii; forms the inlet chamber to the meter and water entering the meter passes first into the chamber lit in any suitable manner such as for example the inlet connection 12s having a passageway l26 therethrough communicating with the chamber H6. This inlet connection may be in the body of the cover member H8 as shown or may be in the body of the casing III as disclosed in the Patent 2,106,651, as will be understood.

A rotating valve I 28, driven by the pistons through the crankshaft 36, directs the flowing fluid alternately through the passageway II4 to the heads of the pistons, or alternately in the other direction from the heads of the pistons and into the central passageway It, as will be described.

The valve I28 has somewhat the shape of an inverted cup, as shown in Figures 1 and 2. As also shown in Figures 1 and 3, a portion of the outer wall of the valve is depressed so as to uncover one of the passageways H4 and place it in open communication with the chamber II B in the cover member H8. The crankshaft 36 protrudes through the upper bushing 32 and terminates in a. reduced portion I35 which fits into a central internal bore I32 in the valve I28. The valve I28 is thus located and guided by the reduced portion I3ii of the crankshaft but the two elements are relatively movable axially as will be explained. A collar I34 is mounted on the crankshaft 36 and secured against rotation by means of a set screw I36. The collar I34 has a bifurcated extension I38, extending radially therefrom, there being a vertical pin I40 passing through but being sealed within the valve I28 and extending through the slot of the bifurcation. A spacer washer I42 surrounds the shaft 36 between the collar I34 and the upper bushing 32 to locate the crankshaft 36 vertically with respect to the bushing. The pin I48 protrudes through the top of the valve I28 as shown in Figure 1, where it is engaged between a pair of spaced, radially extending walls of a slot in a disk I44 affixed to a vertical shaft I 46 journalled for rotation centrally within the cover member I I8, and protruding into a register housing I48 to drive a meter register (not shown).

Figure 3 shows the equiangular disposition of the passageways I I4 around the central passageway IS. The four passageways I I4, each of which is independent from the others, are divided in the regions surrounding the passageway I8 by means of common vertical walls I59, which terminate in the same horizontal plane as the annular surface 20 previously described. The horizontal planar surface thus includes the central annular portion 20, an outer annular portion I52, and the upper surfaces of the vertical walls I50. A one-piece valve seat I55 having the same composition as the piston heads 40 and the retainers 5|] is cemented to the aforesaid horizontal planar surface and further secured against rotation with respect thereto by a series of pins I56. The valve seat I55 is formed from a sheet of uniform thickness, so that its upper surface is coplanar with the horizontal surface including the annular surface 20. A substantially frictionless and yet watertight seat is thus provided between the plastic seat I 55 and the valve I28, which is of cast iron and tends to be self lubricating with respect to the seat I55 because of the graphite in the cast iron.

The open ends of the cylinders I2, I4, etc., are closed and placed in communication with the cylinders I I4 by clinder heads I58 secured to the casing ID by cap screws I60.

The valve I 28, although located by the engagement of the reduced portion I38 of the crankshaft in the bore I32, is held in the top surface of the valve seat I53 solely by its own weight and by the differential pressure between the water in the inlet chamber H6 and the pressure of the liquid on the underside of the valve member. As shown in the drawings, in Figure 1 the valve I28 is so positioned that fluid is being admitted from chamber IIS through a passageway II 4 to the outer end of the cylinder I2. At the same time, fluid is being discharged from the outer end of the cylinder I4, through a passageway II4 to the underside of the valve I28, and thence to the central passageway I8 where it passes vertically downward and through the outlet fitting 94.

At the same time, the passageways II4 to the other two cylinders extending at right angles to the cylinders I2 and I4, are closed by the horizontal portions I32 and IE4 of the valve I28, as shown in Figures 2 and 3. Figure 2 therefore also illustrates the position of the valve I28 when it has rotated through an angle of degrees from the position shown in Figure 1.

I have therefore provided an improved meter for measuring the flow, of fluid through a conduit, the meter being adapted to be inserted into the conduit in any convenient location. By reason of the fact that the fluid enters the meter adjacent the upper portion thereof and, after passing through the meter, is discharged through its lower part, I have eliminated the formation of internal pockets or chambers where impurities may settle out and increase in volume as time goes on to such an extent that they seriously interfere with the operation of the working parts of the meter. Even when there is not a substantial accumulation of such impurities, they are stirred up by the operation of the meter and enter the working parts thereof so that their corrosive and abrasive action will substantially shorten the life of the meter. By making certain parts of the meter of a plastic having a high corrosion resistance as well as low coefficient of friction with respect to the metals which engage it, I have also provided a meter requiring a minimum of replacement parts and having a maximum life.

This invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. 7

What is claimed and desired to be secured by United States Letters Patent is:

In a positive displacement fluid meter, casing structure, a central passageway formed through the lower portion of said casing structure, a plurality of pairs of coaxially aligned cylinders formed in said lower portion of the casing structure radiating in said lower portion of the casing structure radiating from said central passageway and circumferentially spaced about the axis thereof, a piston assembly comprising a pair of opposed pistons rigidly connected for conjoint movement and mounted for reciprocation in each of said cylinder pairs, a stop member fixed to the inner face of each of said pistons, a crank shaft journalied for rotation in said casing structure substantially coaxial with said central passageway, means interconnecting said pistons with said crank shaft to impart rotary motion to the latter from reciprocating movement of the former, a fluid inlet chamber formed in the upper portion of said casing structure, a fluid inlet port opening into said inlet chamber, a Wall separating said inlet chamber from said lower portion of the casing structure having thereon means defining a planar surface within said inlet chamher, an individual passage formed through said wall planar surface and said casing structure lower portion to the outer end of each of said cylinders, an aperture formed in the lowest portion of said casing structure in substantially coaxial alignment with said central passageway, a fitting formed with a central opening received in said aperture to provide a coaxial fluid outlet port in the bottom of said central passageway, said fitting having an upwardly projecting portion extending into said central passageway between said cylinder pairs and defining a stop for said pistons sequentially engaged by said stop members on said pistons to limit inward movement of said pistons, a central opening formed through said wall planar surface and opening into said central passageway in coaxial alignment with said outlet port, and a rotary valve member cooperatively engaging said wall planar surface and driven by said crank shaft to alternately connect said cylinder passageways to said inlet chamber and to said central passageway.

WALTER H. MARSH.

8 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 492,267 Bruce Feb. 21, 1393 1,762,949 Bassett June 10, 1930 1,893,429 McGogy Jan. 3, 1933 1,905,062 Schaeffers Apr. 25, 1933 1,911,521 Marsh May 30, 1933 1,923,790 Moore Aug. 22, 1933 2,035,338 Parker Mar. 24, 1936 2,091,912 DeLancey Aug. 31, 1937 2,106,651 Parker Jan. 25, 1938 2,304,371 Queneau et a1 Dec. 8, 1942 2,332,787 Fleming Oct. 26, 1943 2,338,480 Auxier Jan. 4, 1944 2,351,732 Almond et a1 June 20, 1944 2,356,273 Risser 1 Aug. 22, 1944 2,387,181 Procter Oct. 16, 1945 2,394,243 Joyce Feb. 5, 1946 2,413,034 DejLancey Dec. 23, 1946 2,429,426 Phillips et al Oct. 21, 1947 2,464,499 Gilmore Mar. 15, 1949 FOREIGN PATENTS Number Country Date 471,447 Great Britain Sept. 6, 1937 

